Process for bleaching textile fibers.



UNITED TATE PATENT @FFIQE ALOIS SGHAIDHAUF, OF FRANKFORT-ON-THE-MAIN,GERMANY, ASSIGNOR TO THE ROESSLER & HASSLACHER CHEMICAL (10., OF NEWYORK, N. Y., A. CORPORATION OF NEW YORK.

PROCESS FOR BLEACHING TEXTILE FIBERS.

No Drawing.

To all whom it may concern:

Be it known that I, ALOIS SCHAIDHAUF, a subject of the Emperor ofGermany, and resident of Frankfort on the Main, Germany, have inventedcertain new and useful Improvements in Processes for Bleaching TextileFibers, of which the following is a specification.

This invention relates to improvements in processes for bleachingtextile fibers, such as cotton, by means of alkaline hydrogen peroxidsolutions stabilized by anticatalyzers.

The introduction of the strongly alkaline solutions of sodium peroxidfor bleaching purposes, though easily obtainable, has met with delaybecause of the fact that hydrogen peroxid solutions of strongly alkalinereaction very quickly give off their oxygen.

Furthermore, those sln'lled in the art generally have been of theopinion that textile fibers containing cellulose could not be treatedwith any strongly alkaline agent giving 011? oxygen, without reducingtheir valuable properties.

In the standard text-book The Chemistry of OeZZuZose by Schwalbe, (1911)the following is said on page 143, m:

Again the strongly alkaline solutions are the most detrimental ones.Here sodium peroxid stands in the front line. If dissolved in water oneobtains caustic alkali besides hydrogen peroxid and the detrimentalaction of the former must be counteracted by the addition of acid ormagnesium sulfate unless it is referable to operate with a neutral bathas or instance for such bleaching operation, the purpose of whichconsists strictly in removingdmpurltles only, without simultaneouslyoxidizing the cellulose-fiber.

In view of the points discussed above it has been suggested to achievethe cleaning and simultaneous bleaching of the cotton as well as ofother vegetable fibers with slightly alkaline solutions of materialsgiving ofi oxygen, said solutions being produced by first neutralizingthe stron alkali by a strong acid and then rendering the nearly neutralsolution thus obtained alkaline by adding thereto a salt of a slightalkaline reaction.' (See Deutsche Faerberzeittmg of June 30, 1912, pg.512513.) This latter Specification of Letters Patent.

Patented Aug. "3, 1917.

Application filed October 2, 1913. Serial No. 793,039.

process is both too cumbersome and expensive to compete with theWellknown processes using chlorin as a bleaching agent.

I have endeavored to carry out the bleachingrocess with stronglyalkaline solutions, as o tained for instance when dissolving sodiumperoxid in water, without previously neutralizing the free causticalkali.

I have now found, that this purpose may be achieved if small quantitiesof a soluble magnesium salt, or small quantities of a combination ofmagnesia or magnesium, with silica or silicates respectively, are addedto a solution of a peroxid, preferably so dium peroxid.

The addition may be made before or after preparing the solution of thesodium peroxid; one may add either ready made compounds or one may addthe components of the same to effect the formation of the respectivecompounds in the solution of the peroxid.

With great advantage I may prevent the premature decomposition of theperoxid solution by employing the anticatalyzers in a state in which thelatter are able to difi'use as much as possible within the solution,viz. by employing them in a colloidal or gelatinous form.

In preparing the peroxid solution I may also use natural watercontaining such, anticatalyzers, and to such natural water containing ananticatalyzer in either an insufiicient quantity or only one componentof the same, I may add either the missing quantity of the anticatalyzeror the missing component in order to produce the anticatalytic actionwithin the solution.

I have furthermore made the surprising discovery that the fiber is notaffected in any way by treating it with solutions having a high contentof free caustic alkali if the anticatalytic action, form-ing the subjectmatter of this invention, has been established in said solutions.

The following example will serve for the further elucidation of myinvention. In bleaching cotton for instance I proceed as follows:

100 kilograms of cotton goods are thoroughly wetted whereby they take up200 kilograms of water. In preparing the bleaching bath Idissolve 1.6kilograms of sodium peroxid in 400 liters of Water. To this solution Iadd solutions containing each 0.15 kilograms sodium-silicate and 0.12kilograms of magnesium chlorid, whereupon I finally add 0.4 kilograms ofMonopol-soap, the latter comprising a staple standard soap made bytreating olive oil with caustic potash, a certain amount of Turkey redoil and carbon tetrachlorid having been added to the crude soap. Thebleaching bath then being ready, the wetted cotton-goods are immersed inthe same. I

\Vithin the first hour the temperature is raised up to about 65-6'7 G.and maintained at this point for a further hour;

thereupon it is raised up to about 87 0.,

and the bleaching is continued until the bath is exhausted.

Cottons'of various origins display different behaviors in being bleachedby means of oxygen, inasmuch as some become perfectly 7 white by onesingle treatment, necessitating only a little more bleaching liquor,whereas others require a second treatment. a

By the present invention I succeed 1n bleaching cotton perfectly whitewithout affecting it in the least. I

My new process compares very favorably with the processes using chlorinas a bleaching agent, inasmuch as chlorin is unwholesome, afl'ects thecotton unfavorably and gives cause to losses in weight, thus renderingcotton bleached by my new process superior in every way to that bleachedwlth chlorin. g

The properties of cotton bleached by the present process do not sufi'erin any way or manner, but, on the contrary the cotton exhibits mostremarkable properties in regard to strength and elastlcity.

In bleaching loose cotton by the present process the losses sustained inweight are very considerably lower than those by the old processesemploying the old lye-boil and chlorin bleaching process. y new processis also superior to the chlorin process inasmuch 'as it is free fromdeleterious efiect on the health of the workmen, and is much simpler inits operation without causing any greater expense than said latterprocess.

It is obvious that, while I have explained my invention withreference-to the bleaching of cotton and the claims are especiallyintended to comprehend cotton as one of the fibers which may be treatedby mynew process, nevertheless the principles of the inven tion and thenew process disclosed are just as applicable to other textile fibers asto cotton, as well as to other material which in the modern sense of theterms textile fiber may be understood as such, such material being forinstance straw, wood in either disintegrated form or even in the form ofplates, etc. I do not restrict myself there fore, to the use of theprocess in connection with the bleaching of any particular fibersfurther than the scope of the appended claims demands, and where in theclaims I use the word soluble as qualifying the word anti-catalyzer Imean to use such word in a broad sense including as well col- 2. Theprocess of bleaching textile fibers consisting in treating the fiberswith a solution containing both caustic alkali and a substance carryingavailable oxygen andretarding the decomposition of the latter substancetion of said fibers by said caustic alkali by the presence of ananti-catalyzer of colloidal and simultaneously preventing decompositioncontaining both caustic alkali and available oxygen in the form. ofhydrogen peroxid, and retarding the decomposition of the hydrogenperoxid and simultaneously preventing decomposition of said fibers bysaid caustic alkali by the presence of an anticatalyzer of colloidalform. 1

5. The process of bleaching textile fibers consisting in treating thefibers with a solution containing both caustic alkali and a substancecarrying available oxygen, retarding the decomposition of said lattersubstance and simultaneously preventing decomposition of said fibers bysaid caustic alkali by the addition of a soluble magneslum compoundwhich acts as an anti-catalyzer.

6. The process of bleaching textile fibers consisting in treating thefiber with an alkaline solution containing active oxygen and acting asan antic'atalyzer.

7. The process of bleaching textile fibers -consisting in treating thefibers with a solua colloidal magnesium compound, the latter causticalkali by the addition of a magnesium compound which acts as ananti-catalyzer.

8. The process of bleaching textile fibers consisting in treating thefiber with an alkaline solution containing active oxygen in the alkaliby the addition of a soluble combination of magnesia and silica, saidcombination acting as an anti-catalyzer.

10. The process of bleaching textile fibers consisting in treating thefiber with an alkaline solution containing active oxygen and a colloidalcombination of magnesia and silica acting as an anticatalyzer.

11. The process of bleaching textile fibers consisting in treating thefibers with a solution containing both caustic alkali and availableoxygen in the form of hydrogen peroxid, and retarding the decompositionof the hydrogen peroxid and simultaneously preventing decomposition ofsaid fibers by said caustic alkali by the addition of a combination ofmagnesia and silica, said soluble combination acting as ananti-catalyzer;

12. The process of bleaching textile fibers consisting in treatingthefiber with an alkaline solution containing active oxygen in the formof hydrogen peroxid and a colloidal combination of magnesia and silicaacting as an anticatalyzer.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ALOIS SCHAIDHAUF.

Witnesses:

JEAN Gmmn, 1 CARL GRUND.

